Doc

Author: sourcefrog

src/visit.rs

@@ -116,6 +116,9 @@ fn walk_file(
 
 /// `syn` visitor that recursively traverses the syntax tree, accumulating places
 /// that could be mutated.
+///
+/// As it walks the tree, it accumulates within itself a list of mutation opportunities,
+/// and other files referenced by `mod` statements that should be visited later.
 struct DiscoveryVisitor<'o> {
     /// All the mutants generated by visiting the file.
     mutants: Vec<Mutant>,